Effects of sweet, bitter and soaked micronised bitter lupins on duckling performance

1. The feeding value of sweet white lupins (Lupinus albus variety Hanli), bitter lupins (Lupinus angustifolius) and soaked micronised bitter lupins on male Pekin duckling performance was examined. 2. Four isocaloric and isonitrogenous diets were formulated with 1 containing no lupin and the other 3 containing 400 g/kg sweet, bitter or soaked micronised bitter lupins. The 3 lupin diets were then blended appropriately to produce 16 experimental diets containing 0, 50, 100, 200, 300 and 400 g/kg sweet, bitter and soaked micronised bitter lupins, and fed to Cherry Valley Super M Pekin ducklings for 6 weeks. 3. The feeding of bitter lupins to ducklings at 200, 300 and 400 g/kg diet resulted in a poorer performance (P < 0.01) with regard to body weight gain, food intake and food conversion ratio than feeding the control diet. Carcase moisture was higher and carcase fat content lower (P < 0.01) at the 400 g/kg concentration only. No significant differences were observed with carcase protein or carcase ash content. No significant differences were observed between treatments and the control when different amounts of sweet or soaked micronised bitter lupins were fed. 4. There were significant linear adverse responses (P < 0.01) with bitter lupins in most of the variables studied whereas no responses were observed with sweet or soaked micronised bitter lupins as the concentration of lupins in the diet increased. The soaked micronised bitter lupins performed as well as the sweet lupins, showing that the amount of bitter lupins used in duckling diets can be increased to 400 g/kg after this treatment.